The Euclid project

Cristobal Padilla


The Euclid group at IFAE is lead by Cristobal Padilla, who is the Project Manger of the NISP-FWA and coordinates the group of engineers and technicians to fulfill the Institute responsibilities in Euclid. Some of the postdocs and students in the Cosmology group also help, specially in the preparation of the data and usage of PAU for Euclid science.

Introduction

Euclid is a mission for the European Space Agency (ESA) Cosmic Vision (CV) 2015-25 programme to explore how the Universe evolved over the past 10 billion years to address questions related to fundamental physics and cosmology on the nature and properties of dark energy, dark matter and gravity, as well as on the physics of the early universe and the initial conditions which seed the formation of cosmic structure.

Euclid Goals

To accomplish its goals, Euclid will carry out a wide survey of 15,000 deg2 of the sky free of contamination by light from the Milky Way and the Solar System and a 40 deg2 deep survey to measure the high-redshift universe. The complete survey represents hundreds of thousands of images and several tens of Petabytes of data. Euclid will observe about 10 billion sources out of which more than one billion will be used for weak lensing. Several tens of million galaxy redshifts will be also measured and used for galaxy clustering. With these images Euclid will probe the expansion history of the Universe and the evolution of cosmic structures by measuring the modification of shapes of galaxies induced by gravitational lensing effects of dark matter and the 3-dimension distribution of structures from spectroscopic redshifts of galaxies and clusters of galaxies. Euclid data will provide improvement factors of ~30 in the measurement of the neutrino mass and up to ~400 in the uncertainty of the parameters of the cosmology state equation and will leave legacy catalogs in may areas of galaxy science with exquisite imaging quality and superb Near Infrared Spectroscopy.
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Figure 1: Artist View of the Euclid satellite (Copyright ESA).

Euclid Instruments

The Satellite will be equipped with a 1.2 m diameter Silicon Carbide (SIC) mirror telescope made by Airbus Defense and Space feeding 2 instruments, VIS and NISP, built by the Euclid Consortium. These instruments are a high quality panoramic visible imager (VIS), a near infrared 3-filter photometer (NISP-P) and a slitless spectrograph (NISP-S). The IFAE is responsible for the design and manufacturing of the NISP Filter Wheel Assembly (NISP-FWA), a device that allows the NISP instrument to select the optical filter used for the images it takes.
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Figure 2:
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Figure 3:

IFAE contribution in 2018

During the first half of 2018 the IFAE group has built and fully qualified the Engineering Qualifying Model of the NISP Filter Wheel Assembly

During the first half of 2018 we have built and fully qualified the Engineering Qualifying Model (EQM). This model contained a real fully coated filter and served to completely validate the design of the FWA both in the terms of structural and alignment performance and the validation of the simulations and the optical performance of the filers. The group had to fully commission the Ground Segment Equipment, including an x-y metrology table with the confocal sensor to allow the precise non-contact metrology of the FWA, the interferometer to measure the Wave Front Errors of the filters and the Autocollimator to precisely measure the tip-tilt angle of the filter with respect to the NISP reference surface. All these measurements have been done at operational conditions with the FWA inside the cryostat.

After the successful qualification of the EQM model, we have built and tested (with the same procedures as for the EQM) the Flight Model (FM) that was successfully delivered to the Laboratoire d’Astrophysique de Marseille (LAM), where it was integrated in the NISP-FM. It is expected that the NISP verification tests are done during the first half of 2019 allowing to deliver the NISP Flight Model to ESA in the second half of 2019.

We have also manufactured three spare mounts with their fully flight qualified filters that are kept inside a nitrogen filled sealed aluminum box until Euclid is finally launched.

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Figure 4:

ASTEROID

ASTEROID is an H2020 project aiming at enabling Europe to acquire the technology and knowledge necessary to manufacture 2k^2 high performance Infrared Focal Plane Arrays, define the types of products to design and define the strategy to create an industrial manufacturing line of these detectors. IFAE is partnering with companies and institutions in France and Austria to develop a low noise and low dark current detector that will be directly useful for astronomy application in both ground telescopes (ESO) or space telescopes (ESA).

IFAE’s responsibility is in the optical and electrical characterization of the detector. To perform this task, it will reuse some of the equipment developed for the Euclid project, together with a complete new optical setup. Additionally we have reached an agreement with the European Southern Observatory (ESO) which allow us to use their New Generation Controller (NGC) for the test of the Infrared Sensors. This allows IFAE to acquire the know-how in characterizing IR sensors for Astronomy and Space and establishes a possible link of future collaboration with other ESO missions and their world-class telescopes located in the Atacama Desert in Chile.

IFAE is also responsible for the communication inside ASTEROID. More information can be found in asteroidh2020.eu